Thorin Klosowski

You have a ton of options for writing programs online, but Editorially manages to combine some of the best features of all of them into one, easy to use program where you get a minimalist writing environment, powerful version control, and extensive collaboration features.

Editorially uses Markdown for it's formatting, but otherwise it works like any old plain text editor would. Type your words and Editorially saves them in multiple versions as you go. Then, when you're ready to share, you can invite friends and colleagues to make notes and edits. These notes aren't just little snippets like you'd find in Word or Google Docs, they're full, easy-to-read conversations where a group can actually discuss the text. Editorially is currently in open beta right now where it's free to sign up.